The present invention relates to a game machine, and more particularly, to a position sensor for sensing the position of a self-propelled member employed in a racing game machine or the like. Further, the present invention enables not only simplification of a position sensor which senses the every-changing position of a self-propelled member on a traveling field (i.e., a two-dimensional plane) for controlling trackless travel of the self-propelled member through feedback, but also simplification of computation processing for sensing position information.
A game machine for causing miniatures to travel in cooperation with traveling of self-propelled members includes a racing game machine for causing miniatures to race with each other, a play game machine for causing a miniature to perform various actions, and the like. Of the game machines, some employ a self-propelled member as a miniature; some employ a two-storied structure; and some guide a miniature through use of a self-propelled member. In terms of a travel control method, some game systems control a self-propelled member which is essentially to travel in a trackless manner, through feedback (as described in; e.g., Japanese Patent No. 2861978), and some game systems control a member which is essentially to travel while tracking down a guide line, so as not to deviate from the guide line through feedback (as described in; e.g., Japanese Patent Publication No. 11-244517A).
A game machine which causes a self-propelled member to travel in a trackless manner controls a traveling path of a self-propelled member and an every-changing travel speed of the same in accordance with a program through feedback. The every-changing position of the self-propelled member on a traveling field (two-dimensional plane) is detected, and the traveling path and speed of the self-propelled member are feedback-controlled on the basis of position information.
There are various techniques for controlling trackless travel of a member in a game machine. The outline of a typical position sensor for effecting feedback control is shown in FIG. 1. In the position sensor shown in FIG. 1, X-position sensing lines 2a and Y-position sensing lines 2b are densely provided within the traveling field 1. The X-position sensing lines 2a are connected to an X-position retriever 3a, and the Y-position sensing lines 2b are connected to a Y-position retriever 3b. In this way, a self-propelled member travels over the traveling field 1 within which the X-position sensing lines 2a and the Y-position sensing lines 2b are arranged. The self-propelled member emits a unique signal from its transmitter. The position sensing lines 2a and 2b receive the unique signal and send the thus-received signal to the X-axis and Y-position retrievers 3a and 3b. The received signal is further transmitted to a position detector 4, where the X-coordinate position and Y-coordinate position of the self-propelled member are detected by the position detector 4. The position detecting signal is transmitted to a microcomputer 5. Since the self-propelled member emits a unique signal at predetermined time intervals, the traveling position of the self-propelled member is detected every time the unique signal is emitted.
In the case of a game machine which senses the position of a self-propelled member through use of the position sensing lines 2a and 2b, since the position sensing lines 2a and 2b are arranged within the traveling field 1 densely, manufacturing costs of the game machine are expensive. Laborious operations are required for laying sensing lines within a traveling field. Further, there may arise a case where malfunction may arise for reasons of an open circuit or connection failures. In this case, a plurality of position sensing lines located in the vicinity of one self-propelled member receive signals output from the self-propelled member. Hence, the position sensing lines closest to the self-propelled member are discriminated by the position retrievers 3a and 3b so that the traveling position of the self-propelled member is detected from the signal received by the closest position sensing lines. For this reason, information processing required for effecting position detecting operation is not simple. As mentioned above, this related position sensor is complicated in both hardware and software.
The present invention is aimed at simplifying a sensor for detecting the travel position of a self-propelled member in a game machine and putting considerable thought into a position sensor by utilization of a recent sophisticated information processing and reading technique such that information about the position of a self-propelled member on a traveling field can be read directly.
In order to achieve the above object, according to the present invention, there is provided a game machine, comprising:
a traveling plane, on which a plurality of two-dimensional bar codes are arranged;
a self-propelled member, which travels on the traveling plane so as to trace a programmed traveling path;
a bar code reader, provided in the self-propelled member, for reading information provided with each two-dimensional bar code; and
a position information processor, which detects a travel position of the self-propelled member in accordance with the information read by the bar code reader, and controls a movement of the self-propelled member in accordance with the detected travel position.
A two-dimensional bar code itself has hitherto been known, and a minute two-dimensional bar code which represents predetermined position information through use of a code are arranged in a matrix pattern systematically. Regardless of the direction of a two-dimensional bar code relative to the scanning direction of a two-dimensional bar code reader, code information can be read momentarily without fail. Further, the thus-read code information per se represents the position of the self-propelled member. Hence, information processing required for reading positional information is simple.
Since the printed two-dimensional bar code is scanned by the bar code reader, thereby reading code information representing positional information, a position sensor mechanism can be made considerably simple. Still further, since a read precision of this system is very high, there are substantially no position information read errors. Consequently, costs incurred for manufacturing a position sensor are considerably curtailed in terms of hardware and software.
Preferably, a sheet member on which the two-dimensional bar codes are printed is placed on the traveling field.
In this configuration, an operation required for providing the bar codes is also very simple.
Preferably, the bar code reader reads the information in response to an instruction which is intermittently issued from the position information processor.
Alternatively, it is preferable that the bar code reader reads the information in response to an instruction which is periodically issued from a timer provided with the self-propelled member.
The position information processor may be provided inside or outside of the self-propelled member.
Preferably, the two-dimensional bar codes, each having a substantially square shape, are arranged with a fixed interval which is about twice a side constituting the square.
Since space is interposed between two-dimensional bar codes, occurrence of a failure to read code information can be avoided.
Preferably, each two-dimensional bar code is covered with a transparent resin sheet having a wrinkled surface.
In this configuration, the bar code is protected from friction which arises between drive wheels of the self-propelled member and the bar codes. Hence, abrasion of and damage to the bar code images are surely prevented. Further, the wrinkled sheet surface has a high frictional coefficient. Hence, slippage of wheels of a self-propelled member can be diminished, thereby improving the precision of travel control operation.
If a material of the resin sheet has a high frictional coefficient, the surface may not be wrinkled. Alternatively, the surface frictional coefficient of the resin sheet can be increased by roughening such as satin finishing.
Here, the two-dimensional bar codes may be printed on a lower surface of the resin sheet.
Preferably, a pair of bar code readers are provided in a front lower portion and a rear lower portion of the self-propelled member, respectively.
In this configuration, since code information about two two-dimensional bar codes can be read simultaneously through use of the pair of bar code readers, the orientation of the self-propelled member can be readily detected on the basis of the thus-detected two code information items. Consequently, control of a traveling path, including an operation for turning a self-propelled member at a target point on a scheduled traveling path, becomes simple.
Here, it is preferable that the two-dimensional bar codes are arranged with a fixed interval which is smaller than a distance between the pair of bar code readers.
Preferably, each two-dimensional bar code indicates a position where the bar code situates on the traveling field, which is represented by an X-coordinate position and a Y-coordinate position.
In this configuration, information processing required for detecting the position of the self-propelled member can be made simple.